A dead battery is likely the cause when a watch stops working. We can replace watch batteries for almost any style and brand of watch while you wait. We carry most common battery sizes in stock. We cannot make any guarantee of the same level of water resistance once we have opened the back of your watch. To ensure water resistance, we would have to pressure test the watch, and we do not have the equipment for this. Your watch would have to be sent to the original manufacturer to perform a battery change if you want a professional resealing.